1. Field of the Disclosure
The present disclosure relates to apparatuses and methods to lift and install large-diameter tubulars with a drilling rig. More particularly, the present disclosure relates to apparatuses and methods to raise horizontal sections of large-diameter pipe to mount them atop vertical strings of large-diameter pipe. More particularly still, the present disclosure relates to apparatuses and methods to raise horizontal sections of conductor pipe to install them atop vertical strings of conductor pipe extending into a wellbore.
2. Description of the Related Art
Referring to FIG. 11, a perspective view is shown of a drilling rig 50 used to run tubular members 52 (e.g., casing, drill pipe, etc.) downhole into a wellbore. As shown, drilling rig 50 includes a frame structure known as a “derrick” 54 from which a traveling block 56 and an elevator 58 and/or a top drive (not shown) may be used to manipulate (e.g., raise, lower, rotate, hold, etc.) tubular members 52. As shown, traveling block 56 is a device that is located at or near the top of derrick 54, in which traveling block 56 may move up-and-down (i.e., vertically as depicted) to raise or lower tubular members 52. As shown, traveling block may be a simple “pulley-style” block and may have a hook 60 from which objects below (e.g., elevator 58) may be hung. Additionally, elevator 58 may also be coupled below traveling block 56 and/or a top drive (not shown) to selectively grab or release tubular members 52 as they are to be raised or lowered within and from derrick 54. Typically, elevator 58 includes movable gripping components (e.g., slips) movable between an open position and a closed position (shown in FIG. 11). In the closed position, the movable components form a load bearing ring (or shoulder) about or upon which tubular members 52 may bear and be lifted. In the open position, the movable components of elevator 58 may move away from one another to allow the tubular members 52 to be brought within or removed from elevator 58.
When assembling a string of tubular members 52 together, the tubular members 52 may be removed from a pipe rack 62 and pulled, or otherwise transported, towards an access opening 64, for example, a v-door, within the derrick 54 of the drilling rig 50. The tubular members 52 may be loaded onto a pipe ramp 66 adjacent to the access opening 64, in which a rigidly mounted end stop 68 may abut the ends of the tubular members 52 to support the tubular members 52 up against access opening 64.
Tubular-shaped goods have a variety of uses in oilfield operations including, but not limited to, drill pipe, drill collars, casing, continuous coiled tubing, and the like. One such tubular-shaped good used in exploration and drilling is conductor pipe. Generally, conductor pipe (e.g., drive pipe) is large-diameter pipe (e.g., between about 75 cm to about 100 cm or about 50 cm to about 182 cm in diameter), usually constructed of steel, that extends from the wellhead into the earth or ocean floor. As such, a string of conductor pipe sections (i.e., a conductor string) is typically the first string of “casing” run into the wellbore, and serves to stabilize the sediment surrounding the wellbore to prevent it from caving-in.
Installation of the conductor string may be performed any number of ways. On land, the conductor string may be driven into the ground from above with an impact loading hammer apparatus. In certain locations, excavation may be necessary prior to driving the conductor string into the uncovered sediment. Offshore, conductor strings may similarly be installed, using impact driving and excavation techniques. In undersea environments, conductor strings may be “jetted in”, for example with a pressurized fluid discharged (e.g., seawater) at a distal end of the conductor string displacing the sediment as the conductor string is advanced into the sea floor. Following such a jetting process, an impact driving process may be performed to force the conductor string further into the sea floor, if desired. Additionally or alternatively, in undersea environments, conductor strings may be “sucked” into the sea floor by filling the string with water, sealing the conductor string, and then pumping, or evacuating, the trapped water from the inner bore of the conductor string. As the water is removed from the sealed bore of the conductor string, the conductor is plunged deeper into the sea floor as the sea floor sediment replaces the evacuated water. Following such a suction process, an impact driving process may be performed to force the conductor string further into the sea floor, if desired. Alternatively, impact driving may be performed simultaneously as the conductor string is jetted or sucked into the sea floor.
While conductor strings are relatively the largest (diameter) and shortest (length) strings of casing used to case a wellbore, the strings are still long enough to be assembled from several sections, or joints, of conductor pipe. As such, because of their large diameter and desired permanent placement about the wellbore, conductor strings are typically assembled, on site, from several joints of conductor pipe 20-40 feet long, and may be threaded or welded together end-to-end.
Historically, assembling strings of conductor pipe on the rig floor has been a difficult and time-consuming process. In one example method, to install a new joint of conductor pipe atop a string conductor pipe already engaged into the wellbore, a series of lifting eyes and handling eyes are affixed to the outer periphery of the large diameter and heavy-walled joint of conductor pipe to be added. In particular, a pair of heavy-duty lifting eyes are attached, typically 180° apart near the upper-most end of conductor pipe while it remains horizontal, either in the pipe rack or in another location on or near the drilling rig. Next, at least one pair of handling eyes are added to the joint of conductor pipe to be added, typically at opposite ends of the joint, but at similar radial positions.
As such, using various rigging and sling mechanisms, a crane may secure the bottom end of the horizontal conductor pipe (from a handling eye) while another crane (or the rig draw works) raises the upper end so that the formerly horizontal joint of conductor pipe may be held in a vertical position. Once moved into place atop the string of conductor pipe already engaged into the wellbore (and held in location by its lifting eyes), the joint of conductor pipe to be added may be threaded together and/or welded in place. With the new joint of conductor pipe attached, the lifting eyes of the former topmost joint may be removed and the entire string of conductor pipe may be supported and lowered by the lifting eyes affixed to the outer profile of the newly-added joint. Once the string of conductor pipe is supported by the lifting eyes of the new joint, the handling eyes of the new joint are removed, e.g., to minimize resistance in running the conductor string into the wellbore.
However, the installation and removal of the lifting and handling eyes may be problematic in itself. In many cases, bosses, pre-fabricated with the joint of conductor pipe, contain tapped holes to receive the lifting and handling eyes so that high-strength bolts may be used to transfer the load from the eyes to the joint of conductor pipe. Bosses are typically an external protrusion on the outer surface of the conductor pipe. When it comes time to remove the lifting and handling eyes, the bolts may be removed, however the boss remains. As a machining and welding process, the installation and manufacture of the bosses is both time consuming and expensive. Further, as an upset on the outer profile of the joint of conductor pipe, the bosses may add undesired resistance as the conductor string is driven further into the ground about the proposed wellbore and/or may prevent the sediment from re-settling around the conductor string, e.g., not allowing the sediment to sufficiently retain the conductor string in place. As the bosses are typically welded on and bolted to the lifting and handling eyes, they represent possible failure mechanisms that may disrupt operations should a boss, bolt, or lifting eye fail during the installation procedure.
Alternatively, lifting and handling eyes may be directly welded to the outer profile of the joints of conductor pipe. Following use, the welds may be ground off and the outer profile of the conductor pipe may be ground smoother such that little or no resistance to being driven remains. However, depending on regulations for the particular location, “hot work” such as welding and grinding may not be allowed to be performed at particular times on the rig floor. Additionally, the processes to weld, remove, and grind smooth the outer profiles of the joints of conductor pipe may represent a tremendous amount of time investment. Furthermore, during the removal and grinding process, there is opportunity for the outer profile of the joint of conductor pipe to become damaged to the point where it must be replaced or repaired. Repairing a lower joint of conductor pipe following the installation of an upper joint of conductor pipe would be highly undesirable, and would consume tremendous amounts of time and rig resources.
Apparatuses and methods to simplify the lifting, assembly, and installation of strings of conductor pipe would be well received in the industry. In particular, apparatuses and methods to assemble and install joints of conductor casing without requiring the installation and removal of lifting and handling eyes would be a significant benefit to the industry.